<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>

        .inline-2-block {
            border: solid 1px #ddd;
            display: block;
            margin-bottom: 5px;
        }

        .block-2-inline {
            display: inline-block;
            width: 30%;
            height: 50px;
            border: solid 1px #ddd;
            text-align: center;
            line-height: 3em;
        }

    </style>
</head>
<body>
<a class="inline-2-block" href="">houdunren.com</a>
<a class="inline-2-block" href="">houdunren.com</a>
<a class="inline-2-block" href="">houdunren.com</a>

<a class="block-2-inline" href="">houdunren.com</a>
<a class="block-2-inline" href="">houdunren.com</a>
<a class="block-2-inline" href="">houdunren.com</a>
</body>
</html>